Cross-cultural Adaption and Validation of the Danish Voice Handicap Index.

Objectives: We aimed to assess psychometric properties, including internal consistency, reliability, and clinical validity of the Danish version of the Voice Handicap Index (VHI).

Study Design: A cross-sectional survey study was carried out.

Methods: For validation, the existing nonvalidated Danish version of the VHI was used. Data from 208 patients with voice disorders of different etiology (neurogenic, functional, and structural) and a control group of 85 vocally healthy individuals were included. A test-retest reliability analysis of 42 patients and 45 control persons was performed. The internal consistency, test-retest reliability, and clinical validity of the questionnaire were assessed.

Results: Internal consistency was high with a Cronbach α >0.90 for both the patient and control group. Test-retest reliability measured as intraclass correlation coefficient was good with 0.93 (95% confidence interval [95% confidence interval]: 0.87-0.96) for patients and 0.78 (95% confidence interval: 0.63-0.87) for the control group which indicates sufficient reliability of the questionnaire. The Danish VHI has good clinical validity as it has a strong correlation between patient's perception of the severity of their voice disorder and the VHI score from the Spearman correlation of 0.69.

Conclusion: The existing Danish version of the VHI has been thoroughly validated and found to be in line with the original VHI from Jacobsen et al. It showed good internal consistency, test-retest reliability, and clinical validity. It is suitable for use in daily practice and in research projects as it is able to assess patients' perception of their voice disorder severity.